Relay-locking means



A. G. COOLEY RELAY LOCKING MEANS Filed April 11. 1928 Jan. 7, I930.

i 40 started by an impulse over Patented a... 7, 1930 .ws'rm e. COOLEY, onnnw YORK, 1m. Y. im nnir-nocxme MEANS Application filed April 11 When the contacts ofmechanical relays close there is atendency for-the contacts to re bound, thereby reopening the circuit momntarily and causing unnecessary arcing; and

5 the object of this invention is to provide means to prevent this tendency, which is particularly applicable to apparatus in which the relay is operated or controlled through an audion or amplifier tube of the type having a her current-controlling element.

While the invention has many applications, it is particularly applicable to photo-telegraphic systems.

For the purpose of illustrating the genus 15 of the invention, typical embodiments are shown in the accompanying drawings, in

which Fig. 1 illustrates a system in which the locking potential is obtained from a voltage drop across a resistance in the relay contact circuit,

this potential being applied to the grid of the first tube of a series of amplifiers adapted for direct current amplification Fig. 2 illustrates a modification in which 25 the locking potential is obtained from avoltage drop across a load in the relay contact circuit, and is applied to the tube directly controlling the relay; and

Fig. 3 illustrates still another embodiment in which the lock from a' voltage drop across a resistance produced by the discharge of a normally charged condenser when the relay circuit is closed.

In the particular embodiments chosen for 35 the purpose of illustration, the invention is shown as applied to a photo-telegraphic system in which the drum D at the receiving station is stopped once each revolution and then the-line whenthe corresponding drum at the transmitting station reaches a predetermlned point in each revolution, thereby to maintain the two drums in synchronism. The mechanism diagrammatically illustrated in the drawings for stopping the drum D comprises a plungerv '1 sliding vertically in a guide 2, which is pivoted to swing clockwise about the axis 3 when the relay 4 is energized, thereby to disengage the plunger 1 from the stop 5 on the drum '5 and permit the drum to continue its rotation spring contact [18 connected on one side ing potential is obtained 1928. Serial No. 269,090.

in the direction of the arrow in each figure.

When the stop 5 engages the lower end of the plunger, the plunger is lifted to raise the 6 against a fixed contact, the flange 7/ limiting the upward movement of the plunger, and

oscillated clockwise to disengage the drum, the plunger drops from the position shown in Fig. 1 to the position shown opening the circuit at contact 6.

In Fig. 1 the circuits for controlling the trip magnet 4 comprises a circuit 8 including a source of potential 9, a resistance 10, a relay switch-11, as well as the switch contacts above described. The switch 11 is closed by a relay 12 which receives current through the control or amplifier tubes 13 and 14'comprising grids 15 and '16, filaments 17 and 18,

and plates 19 and 20. A source of potential 22 is connected between the plate 19 and the grid 16, a resistance 23 and a source of potential 24 are connected in series between the 17, and the relay 12 to the plate and on the other side to the source 24. One side 25 of the input circuit is connected to the grid 15 and the other side 26 of the input circuit is connected to one side of the resistance 10, the other side of resistance 10 being connected to the filaments 17 and 18.

e operation of the apparatus shown in Fig. 1 is as follows: When a relay-closing impulse is received over the in-put circuit 25 and 26, it is amplified by the amplifiers 13 and 14 and the amplified impulse causes the relay 12 to close the switch 11. Switch 6 having already been closed by the stop 5 on drum D, the closing of switch 11 completely closes the circuit 8, thereby energizing trip magnet 4 and producing a drop of potential across the resistance 10. This tial is applied to the grid 15 and instantly produces a change in the electrical state of the amplifiers to supply more current to the relay 12, thereby locking the switch 11 closed and preventing rebound. When the trip magnet 4 is energized the plunger 1 and support 2 are swung clockwise about pivot 3 to release the drum D, the plunger 1 and switch contact 6, then descending to the position plate 19 and the filament in Fig. 2, thereby;

when the plunger has been drop of poten- The operation 1 connected. to one side of the switch Thus the condenser the resistance 42 and the potential drop across the resistance 42 is applied to the filameans for changing shown in Fig. 2 to open the circuit of relay 4 as above described. When the circuit 8 is thus opened the relay 12 is unlocked and the switch 11 opens preliminary to another cycle 'of operations as described.

The arrangement shown inFig. 2 is similar to that illustrated in Fig. 1 except in that it is adapted for alternating-current operation and the drop of potential utilized to lock the relay 12 is derived from the load 4 instead of a separate resistance 10. In this figure the input circuit 27 is connected across the primary of a transformer 28, the secondary of which is connected to the grid 29 and filament 30 of the first amplifier tube. The plate 31 of this tube is connected to the primary of a transformer 32 and thence to a source of potential 33 to the filament 30. The secondary of the transformer 32 is connected on one side to the grid 34 of the second amplifier tube and on the other side to a point 35 which completes the circuit to the filament 37 through the trip magnet 4. relay 12 is connected on one side tothe plate 36 and on the other side to the battery 33. of this modification will be evident inasmuch as it is similar tothat of Fig. 1 except in that the drop of potential for locking relay 12 is the drop across the load 4 instead of'resistance 10.

In the arrangement shown in Fig. 3 the input circuit 40 is connected on one side to the grid 41 and on the other side to the resistance 42 and the condenser 43. The relay 12 is connected through a battery 44 to the filament 45 and on the other side to the plate 46. The other side of the resistance 42 is 47 and to the filament 45, switch being connected to the condenser 43. 43 discharges through ment 45 and the grid 41. The condenser 43 is charged by battery 48 and when the switch 47 closesthe condenser is discharged through the resistance 42, thereby applying increased potential to the grid 41 to prevent the'switch 47 from rebounding when it pulls up.

It is understood that the input circuits 25-26 and 40 are complete electrical circuits that will permit the flow of direct current to PM the grid of the tube 13 or 49.

In View of the above illustrations of typical embodiments of the invention, many other applications of the invention will be evident to those skilled in the art.

I claim: v

1. Apparatus of the character described. comprising a tube or: the type having a current controlling element, a relay responsive to changes in the electrical state of said element, a circuit controlled by said relay,'and the electrical state of to supply more energ said element when said circuit is closed by said relay to maintain the circuit closed.

2. Apparatus of the character described comprising a relay, a controller for energizing the relay, a circuit closed by the relay, a source of energy in said circuit, and a r'eedback connection between said circuit and said controller whereby said source causes said controller to supply more energy to said relay the moment it is closed. 4

3. Apparatus of the character described comprising a relay, an amplifier for energizing the relay, a circuit closed by the relay, means for instantly causing the amplifier to the relay when said circuit 18 closed by t e relay, and means responsive to the closing of said circuit for subsequently openingthe circuit.

4. Apparatus of the class described comprising a relay, acontroller for energizing the relay, a c1rcu1t closed by the relay, a source of energy in said circuit, a feed-back A connection between said circuit and said controller whereby said source causes said controller to supply more energy to said relay the moment it is closed, and means responsive to the closing of said circuit for subsequently opening the circuit.

Si ned by me at NewYork, New York, this ourth day of April, 1928.

" AUSTIN G. COOIJEY.

the other side of the 

